Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds real behavioral substance beyond that: the seed derivation (Brahma planet via house.brahma), the per-sign durations (7y movable / 8y fixed / 9y dual), the equal 12-fold sub-split, the 365.256364d sidereal year basis, and the 20-credit cost.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The definition is a single dense, front-loaded paragraph that leads with the system identity, then the algorithm, then the metadata block. Every clause carries domain information, though the jargon density (house.brahma, Jaimini rasi-rules) is heavy for a general reader.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need not be explained, and annotations cover the safety profile; the description supplies the algorithmic grounding an astrologer would need to interpret the periods. It falls short only on selection guidance relative to the many sibling dasha tools.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% (birth-data block, fields, precision all documented in the schema), so the schema does the heavy lifting and the baseline is 3. The description adds no parameter-level meaning — nothing about which inputs affect the Brahma-planet seed or the targetDate/targetTime fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the specific system (Sthira Dasha, the Jaimini fixed rasi-dasha) and describes the output as a Mahadasha sequence that 'walks 12 signs forward', which is a concrete verb+resource. It does not, however, explicitly distinguish this tool from its sthira_antar/pratyantar/sookshma siblings — it even mentions sub-periods, which belong to the deeper-level tools, creating slight ambiguity about scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no statement of when to choose this tool over the other dasha systems (vimshottari, chara, yogini, etc.) or over the other Sthira levels. No prerequisites or exclusions are given; the only routing signal is the tool name and the bracketed group/endpoint metadata.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.